1. Field of the Invention
The present invention relates to a projection display apparatus having a plurality of light sources.
2. Description of the Related Art
Previously, in a projection display apparatus having a plurality of light sources, a projection may be performed by lighting light sources whose number is smaller than the total number of light sources in some cases. For example, in the projection display apparatus having two light sources, the projection is performed by using one light source to be able to extend the time capable of performing the projection simply twice without exchanging the light sources as the projection display apparatus. In addition to extend the time capable of performing the projection in the projection display apparatus, the projection can be continued by switching the light sources without exchanging the light sources as the projection display apparatus when the lifetime of the light source comes during the use in a conference or the like.
In Japanese Patent Laid-Open No. 09-096786, a technology in which the light source is selected to be used so that the accumulated lighting time of each light source is averaged to be able to exchange each light source around the same time is proposed.
However, as the technology proposed in Japanese Patent Laid-Open No. 09-096786, when the light source is selected to be used so that the accumulated lighting time of each light source is averaged, there is a merit that can exchange the light sources around the same time, but there is also a demerit that the lifetime of each light source comes around the same time. For example, when the lifetime of the light source comes during the use of a conference or the like, the projection display apparatus can be continuously used by switching the light sources. However, the lifetime of the switched light source may also come. When the projection display apparatus is installed on a ceiling or the like, it takes much time to exchange the light sources. In this case, the lifetime of the remaining light source also comes before the light source whose lifetime has come is exchanged, and the projection display apparatus may not be able to be used until the light source is exchanged.